JP5742558B2 - POSITION DETERMINING DEVICE, NAVIGATION DEVICE, POSITION DETERMINING METHOD, AND PROGRAM - Google Patents

Description

  The present invention relates to a position determination device, a navigation device, a position determination method, and a program, and more particularly, to a position determination device, a navigation device, and a position determination that determine a position of a vehicle on a map using a landscape image taken from an in-vehicle camera. It relates to methods and programs.

  Conventionally, as this type of position determination device, pattern information indicating road markings such as white lines on the road and position information indicating the coordinates of the feature points of the road markings (world coordinates) are registered in advance, When it is determined by pattern matching using pattern information that there is a road marking in the image captured by the in-vehicle camera, feature points are extracted from the captured image, and the vehicle coordinate system is based on the provisional current position of the vehicle. It has been proposed to calculate the coordinates of the feature points of the road marking (vehicle coordinates), and to calculate the current position of the vehicle using the calculated vehicle coordinates of the feature points of the road marking and the corresponding position information (for example, Patent Document 1). With this device, it is possible to calculate the current position with higher accuracy than the provisional current position of the vehicle obtained by the position measurement using the GPS signal, the gyroscope, and the signal from the lane sensor.

JP 2007-108043 A

  However, the characteristic part of the landscape image from the vehicle, which is performed for the purpose of matching the pattern information indicating the road marking performed by the above-described device with the photographed image and calculating the current position with high accuracy as in the above-described device. Since it is necessary to perform the matching process between the pattern information indicating the captured image and the captured image while the vehicle is traveling, the vehicle position may not be correctly determined. While the vehicle is traveling, depending on the traveling environment, the speed of movement of the road markings and characteristic parts in the captured image increases, and the time required to obtain a captured image that matches the pattern information decreases. That is, when the range of the shooting position on the road where a captured image that matches the pattern information can be obtained becomes narrow, the chance that it is determined that the pattern information and the captured image match is reduced. was there.

  The position determination apparatus, the position determination method, and the program of the present invention are mainly intended to determine the position of a vehicle on a map more appropriately.

  The position determination apparatus, navigation apparatus, position determination method, and program of the present invention employ the following means in order to achieve the main object described above.

The position determination device of the present invention is
A plurality of reference data obtained by extracting characteristic parts of a landscape image taken from an in-vehicle camera at intervals in the traveling direction on the road are stored in association with the corresponding positions on the map, and taken from the in-vehicle camera. Matching processing is performed to determine whether or not the scenery image to be matched and the plurality of reference data match, and based on the position on the map corresponding to the reference data determined to match by the matching processing A position determination device for determining a position of a vehicle on a map,
The interval on the road of the adjacent reference data is adjusted to be shorter as the width of the road is smaller,
It is characterized by that.

  In the position determination device according to the present invention, the interval between adjacent reference data on the road is adjusted so as to be shorter as the width of the road is smaller. When the width of the road on which the vehicle is traveling is relatively small, the moving speed of a characteristic portion in the landscape image (for example, a building beside a road or a roadside feature such as a road sign) is relatively large. The time during which a landscape image having a characteristic portion that matches the reference data can be taken is short. Therefore, in such a case, by shortening the interval on the road between the adjacent reference data, it is possible to increase the chance that the scenery image and the reference data are determined to match by the matching process. As a result, the position of the vehicle on the map can be determined more appropriately.

  In such a position determination apparatus of the present invention, the interval between the adjacent reference data on the road may be adjusted so as to be shorter as the curvature radius of the road is smaller. This is because when the radius of curvature of the road on which the vehicle is traveling is relatively small, the moving speed of the characteristic part in the landscape image (especially the moving speed in the direction opposite to the turning direction of the vehicle). Is based on the relatively large.

  In the position determination device of the present invention, the interval between adjacent reference data on the road tends to be shorter as the number of road lanes is smaller, the distance between roads is narrower, and the sidewalk width of the road is narrower. It can also be adjusted to be at least one of the tendency to become shorter. This is because the smaller the number of road lanes, the narrower the lane width of the road, the narrower the sidewalk width of the road, the smaller the width of the road and the smaller the width of the road on which the vehicle is traveling. Based on the fact that the moving speed of the characteristic part in the landscape image tends to increase.

  Furthermore, in the position determination apparatus of the present invention, the interval between the adjacent reference data on the road may be adjusted so as to be shorter as the distance from the nearest intersection on the road is shorter. This is because when the distance from the nearest intersection on the running road is relatively short, the distance traveled after the vehicle turns right and left at the intersection and enters the road diagonally with respect to the road direction is short. In such a case, the moving speed of the characteristic part in the landscape image (especially the moving speed in the direction corresponding to the direction opposite to the turning direction of the vehicle) is relatively high.

  Alternatively, in the position determination device according to the present invention, the matching processing is performed between determination data obtained by performing predetermined image processing for extracting a characteristic part from a landscape image photographed from a vehicle-mounted camera and the reference data. When the degree of matching is greater than or equal to the determination threshold, it is determined that they match, and when the degree of matching is less than the determination threshold, it is determined that they do not match. The adjusted adjacent reference data may be adjusted to tend to be smaller as the interval on the road is shorter. In this way, when the interval between adjacent reference data on the road is relatively short, it is possible to further increase the chance that the scenery image and the reference data are determined to match by the matching process. Here, as the predetermined image processing, one including at least edge detection processing can be used.

  In the position determination apparatus of the present invention that adjusts the threshold for determination, the threshold for determination tends to decrease as the vehicle speed increases, tends to decrease as the steering wheel steering amount increases, and in the width direction of the running road. At least of the tendency that the vehicle position is closer to the side of the road, the vehicle position is smaller in the width direction of the running road and the vehicle position is closer to the side of the road than the vehicle position at the time of taking the landscape image obtained from the reference data. It can also be adjusted to become either. This is because when the steering wheel amount is large, the vehicle position in the width direction of the running road is closer to the side of the road, and the landscape position is obtained when the vehicle position is obtained in the width direction of the running road. This is based on the fact that the moving speed of the characteristic part in the landscape image tends to increase as the distance from the vehicle position increases.

  The navigation device of the present invention extracts the characteristic portion of the landscape image taken from the in-vehicle camera at intervals in the traveling direction on the road, that is, the position determination device of the present invention of any of the above-described aspects. A plurality of reference data obtained in association with the corresponding positions on the map, and matching for determining whether or not the landscape image photographed from the in-vehicle camera matches the plurality of reference data A position determination device that performs a process and determines a position on a map of a vehicle based on a position on a map corresponding to the reference data determined to be matched by the matching process, wherein the position of the adjacent reference data The position on the road is provided with a position determination device that is adjusted to tend to be shorter as the road width is smaller, and the position on the map of the vehicle determined by the position determination device is It has carried out the route guidance to the destination, and summarized in that.

  Since the navigation device of the present invention includes the position determination device of the present invention according to any one of the aspects described above, it is possible to more appropriately determine the effect of the position determination device described above, for example, the position of the vehicle on the map. The same effects as those that can be achieved can be achieved.

The position determination method of the present invention includes:
A plurality of reference data obtained by extracting characteristic parts of a landscape image taken from an in-vehicle camera at intervals in the traveling direction on the road are stored in association with the corresponding positions on the map, and taken from the in-vehicle camera. A matching process for determining whether or not the scenery image to be matched and the plurality of reference data match, and a position on the map corresponding to the reference data determined to match by the matching process Determining a position on a map of the vehicle based on a position determination method comprising:
The interval on the road of the adjacent reference data is adjusted to be shorter as the width of the road is smaller,
It is characterized by that.

  In the position determination method of the present invention, the interval between adjacent reference data on the road is adjusted to be shorter as the road width is smaller. When the width of the road on which the vehicle is traveling is relatively small, the moving speed of a characteristic portion in the landscape image (for example, a building beside a road or a roadside feature such as a road sign) is relatively large. The time during which a landscape image having a characteristic portion that matches the reference data can be taken is short. Therefore, in such a case, by shortening the interval on the road between the adjacent reference data, it is possible to increase the chance that the scenery image and the reference data are determined to match by the matching process. As a result, the position of the vehicle on the map can be determined more appropriately.

  The program of the present invention is for causing one or more computers to realize each step of the above-described position determination method. This program may be recorded on a computer-readable recording medium (for example, hard disk, ROM, FD, CD, DVD, etc.), or from a computer via a transmission medium (communication network such as the Internet or LAN). It may be distributed to another computer, or may be exchanged in any other form. If this program is executed by one computer or shared by a plurality of computers, each step of the above-described position determination method is realized, so that the same effect as that of the position determination method can be obtained.

1 is a configuration diagram showing an outline of a configuration of a navigation system 10 including a navigation device 20 as an embodiment of the present invention. It is explanatory drawing explaining an example of a mode that the reference data used for the matching process with a landscape image are produced. It is explanatory drawing explaining an example of several relationship with a road, its width | variety Dw, sidewalk width Pw, and lane width Lw. It is a flowchart which shows an example of the reference data space | interval setting method. It is explanatory drawing which shows an example of distance Dc from the nearest intersection in an object road. It is explanatory drawing explaining an example of the some relationship between the parameter for setting the reference data space | interval D, and a coefficient. It is explanatory drawing explaining an example of a mode that a vehicle turns left at an intersection and drive | works. 3 is a flowchart showing an example of a vehicle position determination processing routine executed by an electronic control unit 30. It is explanatory drawing explaining an example of the some relationship between the parameter and coefficient for setting the threshold value for determination Mref. It is explanatory drawing for demonstrating the example of the map for coefficient setting of the travel lane coefficient k14. It is explanatory drawing for demonstrating the example of a mode that the driving lane vehicle coefficient k15 is set.

  Next, the form for implementing this invention is demonstrated using an Example.

  FIG. 1 is a configuration diagram showing an outline of a configuration of a navigation system 10 including a navigation device 20 as an embodiment of the present invention. The navigation system 10 according to the embodiment includes an in-vehicle device 12 centering on various sensors mounted on a vehicle (automobile) (not shown) and a navigation device 20 that operates by receiving power supply from an in-vehicle battery (not shown). As shown in the drawing, the navigation device 20 of the embodiment has a rectangular screen for displaying characters and images, for example, a display 22 configured as a liquid crystal display, an organic electroluminescence display, and the like, and is attached to the screen of the display 22. For example, a touch panel 24 using a resistance film method or a capacitance method, an electronic control unit 30 for controlling the entire apparatus, and a hard disk drive (hereinafter referred to as HDD) 40 as a large-capacity memory for storing various application software and map data. With.

  The electronic control unit 30 is configured as a microprocessor centered on the CPU 32. In addition to the CPU 32, the ROM 34 that stores various processing programs, the RAM 36 that temporarily stores data, and the nonvolatile that holds the stored data. Flash memory 38 and an input / output port (not shown). In addition to the signal from the touch panel 24 for detecting the touch position of the operator and the data read from the HDD 40, various signals from the in-vehicle device 12 are input to the electronic control unit 30 via the in-vehicle network via the input port. Yes. The signal from the in-vehicle device 12 includes a signal from a GPS receiver 50 that receives a signal from a GPS (Global Positioning System) satellite via a GPS antenna, and a pulse signal every time a vehicle drive shaft or wheel rotates a certain amount. A signal from the vehicle speed sensor 52 that outputs a signal, a signal from the acceleration sensor 54 that detects the acceleration of the vehicle, a signal from the direction sensor 56 that includes, for example, a gyro sensor that detects the traveling direction of the vehicle and its change, a vehicle handle A signal from a steering amount sensor 58 that detects a rotation amount (rotation angle) from a reference position (a position corresponding to the traveling direction) as a steering wheel steering amount, a moving image or a still image of a landscape image installed in front of the vehicle There is a signal (captured image) from the camera 59 that can be photographed. From the electronic control unit 30, a display signal to the display 22, an audio signal to the speaker 26 with a built-in amplifier, data to be written to the HDD 40, and the like are output via an output port.

  In the navigation device 20 of the embodiment, the electronic control unit 30 reads out necessary application software and map data from the HDD 40 and executes various processes. For example, as shown in the functional block of FIG. 1 representing functions realized by hardware, software, or a combination thereof, the electronic control unit 30 is based on a signal from the GPS receiver 50, a signal from the direction sensor 56, or the like. Location processing by the location processing unit 60 that determines the vehicle position that is the current position of the vehicle, map display processing by the map display processing unit 62 that displays a map on the display 22 using map data, and the purpose from the determined vehicle position Searching for a travel route to the ground, displaying a map by the map display processing unit 62, navigation processing by the navigation processing unit 64 that provides route guidance by voice output from the speaker 26, and various images by the image processing unit 66 used for these processings Execute processing. The map data is stored in a map data database (hereinafter referred to as map data DB) 42 of the HDD 40.

  In the location processing by the electronic control unit 30, the vehicle position is calculated by so-called GPS navigation based on the GPS signal from the GPS receiver 50, or the vehicle speed pulse signal or acceleration from the vehicle speed sensor 52 when the GPS signal cannot be received. Map data when the vehicle position is calculated by so-called autonomous navigation based on the acceleration of the vehicle from the sensor 54 and the vehicle direction from the direction sensor 56, or when the calculated vehicle position deviates from the road on the map. The vehicle position is estimated by performing so-called map matching that corrects the vehicle position to a position on the road using. Further, in the location processing, matching processing is performed as image recognition processing for determining whether or not a landscape image photographed by the camera 59 matches a plurality of reference data stored in the HDD 40 in advance. The position on the map associated with the reference data determined to be correct is determined as the correct vehicle position instead of the vehicle position estimated by GPS navigation, autonomous navigation, or the like. Here, the plurality of reference data stored in the HDD 40 are feature points of a landscape image taken at intervals in the traveling direction on the road from an in-vehicle camera of the vehicle that actually traveled (for example, the outline of a roadside building, a window Data obtained by extracting roadside features such as frames, signboards and road signs, road markings, etc.), together with shooting information such as the position of the vehicle when shooting a landscape image, and a reference data database of the HDD 40 ( (Hereinafter referred to as reference data DB) 44.

  Here, a method for creating reference data used for matching processing with a landscape image photographed by the camera 59 will be described. FIG. 2 is an explanatory diagram for explaining an example of creating reference data used for matching processing with a landscape image. In the embodiment, as shown in the upper part of the figure, the reference data creation vehicle travels while taking a landscape image in front of the vehicle from the in-vehicle camera with a reference data interval D predetermined for each point on the road, The position (latitude and longitude) of the vehicle on the map at the time of taking a landscape image and the azimuth (azimuth along the road direction) of the vehicle are acquired as accurate information based on signals from various sensors. Subsequently, as shown in the lower left part of the figure, the feature point of the landscape image is extracted and binarized by performing an edge detection process etc. on the photographed landscape image by the on-board electronic control unit A point image is created, and the feature point image is subjected to enhancement processing that emphasizes feature points suitable for landscape image recognition and discards feature points around the emphasized feature points, noise removal processing, etc. Create reference data. In addition, when creating reference data from a photographed landscape image, the feature point image is emphasized so that road markings such as white lines and arrows on the road are emphasized. Detects the driving lane. Detailed descriptions of well-known image processing methods such as edge detection processing, enhancement processing, and noise removal processing are omitted. The plurality of reference data created in this manner are stored in the reference data DB 44 of the HDD 40 of the navigation device 20 mounted on the vehicle of the embodiment, as shown in the right side of the middle stage in the drawing, for each reference data, And the driving lane (hereinafter referred to as the shooting position, shooting direction, and driving lane at the time of shooting), respectively.

  The map data DB 42 of the HDD 40 includes road information, facility information, and the like. The road information includes, for example, the position (latitude and longitude) on the map indicated by the nodes at both ends of each road, the distance of each road, and the region. (Urban area, suburb), type (general road, highway), slope, number of traffic lights, as shown on the lower right side of FIG. 2, the width Dw, the number of lanes Ln, the lane width Lw, the sidewalk width Pw, road shape (straight line or curve), radius of curvature R, road type (one-way road, two-way road, road with a median, etc.), the aforementioned reference data interval D, and the like are included. FIG. 3 is an explanatory diagram illustrating an example of a plurality of relationships between a road and its width Dw, sidewalk width Pw, and lane width Lw. In the figure, (a) on the left shows a road with a road type of two-way traffic and a lane number Ln of 6 on one side, and the center (b) shows a one-way road (for example, an expressway or an elevated road). And the right side (c) shows a road with a road type of one-way and a lane number Ln of 4. In FIG. 3, the sidewalk width Pw of the road is the same on both the left and right sides and the lane width Lw is the same. However, if all roads are based on the same standard, for example, the sidewalk width Pw is the left and right sidewalk width. Or the lane width Lw may be expressed as an average value of the lane widths of all lanes.

  Further, a method for setting the interval on the road of the reference data used for the matching process with the landscape image photographed by the camera 59 will be described. FIG. 4 is a flowchart illustrating an example of the reference data interval setting method according to the embodiment. This method is applied when the reference data interval D is set by a computer (not shown) having the same database as the reference data DB 44 before the vehicle for generating reference data travels with taking a landscape image.

  In the reference data interval setting method of FIG. 4, first, the number of lanes Ln, the lane width Lw, the sidewalk width Pw, the road shape, the curvature radius R, the target of the road for which the reference data interval D is set (hereinafter referred to as the target road). Data necessary for setting such as the distance Dc from the nearest intersection on the road and the initial value D0 of the reference data interval are input (step S100), and based on the input parameters of the number of lanes Ln, lane width Lw, and sidewalk width Pw. A lane number coefficient k1, a lane width coefficient k2, and a sidewalk width coefficient k3 to be multiplied by the initial value D0 are set (step S110). Here, the number of lanes Ln, the lane width Lw, the sidewalk width Pw, the road shape, the radius of curvature R, and the distance Dc from the nearest intersection on the target road can be input from the map data DB 42 of the HDD 40. In the embodiment, the distance Dc from the nearest intersection on the target road is determined for each of a plurality of points divided between the nodes at both ends of the target road for each unit distance, and the relationship with other roads and the position of the target road , The data calculated based on the distance and stored in the map data DB 42 are input. FIG. 5 shows an example of the distance Dc from the nearest intersection on the target road. In addition, in the embodiment, the initial value D0 of the reference data interval is accurate on many roads that are target roads within a range in which the calculation amount of the electronic control unit 30 included in the navigation device 20 of the embodiment is not excessive due to location processing. As the distance on the road from which the vehicle position can be obtained, a predetermined distance (for example, several tens of meters) based on experiments and analysis based on the performance of the electronic control unit 30 and the HDD 40 is used.

  Subsequently, the road shape of the target road is examined (step S120). When the road shape is a curve shape, a curvature radius coefficient k4 to be multiplied by the initial value D0 is set based on the input curvature radius R (step S130). When the road shape is a straight line shape, a value 1 is set to the curvature radius coefficient k4 (step S140). Further, an intersection distance coefficient k5 to be multiplied by the initial value D0 is set based on the input distance Dc from the nearest intersection (step S150), and the lane number coefficient k1, the lane width coefficient k2, and the sidewalk width coefficient k3 are set to the initial value D0. And the curvature radius coefficient k4 multiplied by the intersection distance coefficient k5 are set as the reference data interval D (step S160), and the setting is completed. Then, the setting of the reference data interval D is repeatedly performed on all roads on a predetermined map as target roads. Next, setting of each coefficient based on parameters for setting the reference data interval D (in the embodiment, the number of lanes Ln, the lane width Lw, the sidewalk width Pw, the radius of curvature R, the distance Dc from the nearest intersection) will be described. To do.

  FIG. 6 is an explanatory diagram illustrating an example of a plurality of relationships between parameters and coefficients for setting the reference data interval D. As shown in the figure, the smaller the lane number Ln of the target road, the smaller the lane number coefficient k1 across the value 1, and the smaller the lane width Lw of the target road, the smaller the lane width coefficient k2 across the value 1, The narrower the sidewalk width Pw of the road, the smaller the sidewalk width coefficient k3 across the value 1, and the smaller the radius of curvature R of the curve-shaped target road, the smaller the radius of curvature coefficient k4 across the value 1, which is the closest to the target road. Each coefficient is set based on each parameter so that the shorter the distance Dc from the intersection is within a range less than a predetermined distance D1, which will be described later, the smaller the intersection distance coefficient k5 is within a range less than 1. As for the sidewalk width coefficient k3, when the sidewalk width Pw is 0 and there is no sidewalk on the target road, a lower limit value less than a predetermined value 1 of the sidewalk width coefficient k3 is set. As for the intersection distance coefficient k5, the value 1 is set when the distance Dc from the nearest intersection is equal to or greater than the predetermined distance D1. The reason for setting each coefficient in this way will be further described.

  When the width of the road on which the vehicle equipped with the navigation device 20 of the embodiment is traveling is relatively small, the moving speed of the feature points in the landscape image captured by the camera 59 is relatively large, and the reference data DB 44 The time during which a landscape image having a feature point that matches the reference data can be taken is extremely short. In other words, in such a case, the range of the shooting position on the road where a landscape image having a feature point matching the reference data in the reference data DB 44 can be shot is quite narrow. For this reason, the opportunity to determine that the landscape image and the reference data match by the matching process is reduced, and this is true even though the landscape image may be originally recognized as matching the reference data. A so-called recognition failure that cannot be recognized occurs. On the other hand, when the width of the road is relatively small, if the interval D on the road between adjacent reference data is shortened, there is an opportunity to determine that the scenery image and the reference data match by the matching process. Can be increased. As a case where the width of the road is relatively small, it is possible to consider a case where the number of lanes of the road is small, a case where the lane width is narrow, a case where the sidewalk width is narrow, etc. In the embodiment, the number of lanes Ln of the target road is small. As the lane width Lw is narrower and the sidewalk width Pw is narrower, each coefficient is set to be smaller and the reference data interval D is shortened so that the scenery image and the reference data are matched by the matching process. Can be increased. Moreover, since the reference data interval D is lengthened when the width of the target road is relatively large, the data amount of the reference data can be suppressed.

  Further, when the road on which the vehicle on which the navigation device 20 is mounted is running is curved and the radius of curvature R is relatively small, the moving speed of the feature point in the landscape image taken by the camera 59 (particularly the turning of the vehicle) (Moving speed in a direction corresponding to the direction opposite to the direction) is relatively large, and the time during which a landscape image having a feature point that matches the reference data can be taken is extremely short. On the other hand, since the curvature radius coefficient k4 is set to be smaller as the curvature radius R of the target road is smaller, it is possible to increase the chance that the scenery image and the reference data are determined to match by the matching process. Therefore, it is possible to suppress the recognition failure of the landscape image (increase the recognition rate). Further, as can be seen from the example of the vehicle shown in FIG. 7 turning left at the intersection, the vehicle enters the road diagonally with respect to the road direction when the vehicle turns right or left at the intersection and enters the road. However, after the vehicle has traveled to some extent, the vehicle travels in a direction that substantially matches the road direction. For this reason, in the embodiment, since the intersection distance coefficient k5 is set to be smaller as the distance Dc from the nearest intersection on the target road is shorter than the predetermined distance D1, the landscape image and the reference data are obtained by the matching process. It is possible to increase the chances of being determined to match, and to suppress the recognition failure of the landscape image. Therefore, the predetermined distance D1 can be a distance determined in advance through experiments and analysis as a distance until the vehicle travels in a direction substantially coincident with the road direction on the road on which the vehicle that has turned right or left enters the intersection. Since the reference data interval D is set by multiplying each coefficient set in this way by the initial value D0, it is suppressed that it is determined that the landscape image captured by the camera 59 and the reference data do not match by the matching process. And the vehicle position can be determined more appropriately.

  Next, the operation of the navigation device 20 of the embodiment configured as described above, particularly the operation when determining the position of the vehicle during traveling will be described. FIG. 8 is a flowchart showing an example of a vehicle position determination processing routine executed by the location processing unit 60 of the electronic control unit 30 in cooperation with the image processing unit 66. In this routine, the current vehicle traveling direction (direction along the road direction) based on the vehicle position estimated by GPS navigation, autonomous navigation, or the like and the signal from the direction sensor 56 is referred to the reference data DB 44, respectively. It is repeatedly executed every time the shooting position and the shooting direction associated with one of the data match.

  When the own vehicle position determination processing routine is executed, the CPU 32 of the electronic control unit 30 first takes an image of the estimated own vehicle position, which is the currently estimated own vehicle position, by the camera 59 when this routine is executed. Data for determination obtained from a landscape image, estimated vehicle position and reference data of shooting position and shooting direction that coincide with the current vehicle traveling direction (hereinafter referred to as vehicle traveling direction), estimated vehicle position and vehicle traveling direction Based on the shooting lane Ls corresponding to the shooting position and shooting direction, the road type corresponding to the estimated vehicle position and the vehicle traveling direction, the reference data interval D at the estimated vehicle position, and the signal from the vehicle speed sensor 52. For the determination such as the calculated vehicle speed V, the steering wheel steering amount St obtained as a signal from the steering amount sensor 58, the determination reference threshold value M0 used in this determination processing, and the like. It executes a process of inputting the relevant data (step S200).

  Here, in the embodiment, the estimated vehicle position is input by the location processing unit 60 estimated by GPS navigation, autonomous navigation, or the like. For the determination data, the same image processing method used when the reference data is created from the landscape image described with reference to FIG. 2 is applied to the landscape image captured by the camera 59 when this routine is executed. It was supposed to input what was created. The reference data and the shooting travel lane Ls are input from the reference data DB 44 corresponding to the shooting position and shooting direction corresponding to the estimated own vehicle position and vehicle traveling direction, respectively. The road type corresponding to the estimated vehicle position and the vehicle traveling direction is input from the map data DB 42. The reference data interval D is an estimated self-estimated value that is set for each target road and each point in the target road by the reference data interval setting method described with reference to FIG. 4 and stored as part of the road information in the map data DB 42. The input corresponding to the vehicle position is assumed. The determination reference threshold value M0 is a determination in the process of this routine (that is, the matching process of the embodiment) for determining whether or not the matching rate Mr indicating the degree of matching between the determination data and the reference data is equal to or greater than the determination threshold value Mref. The reference value of the threshold value Mref for use is a value that is determined in advance through experiments and analysis as a relatively small value within a range where it can be determined that the determination data and the reference data match.

  When the data is input in this way, the same method as the image processing method when the driving lane is detected when the reference data described with reference to FIG. 2 is generated, and when the determination data is generated from the landscape image photographed by the camera 59 To detect the travel lane Lr on the road on which the vehicle is traveling (step S210), and subtract the captured travel lane Ls from the detected travel lane Lr to obtain the absolute value of the travel lane difference ΔL. (Step S220). Here, in a country or region where the automobile is on the left side like Japan, the driving lane Lr is the value of the leftmost lane as the value 1 and the value from the left side when the road on which the vehicle is driving has multiple lanes. The first lane is a value indicated by an integer, and the value is 1 when the road on which the vehicle is traveling has only one lane. The shooting lane Ls as shooting information in the reference data DB 44 is also an integer equal to or greater than 1.

  Subsequently, based on the input reference data interval D, vehicle speed V, steering wheel steering amount St, detected travel lane Lr, and calculated travel lane difference ΔL, an interval coefficient k11 to be multiplied by the determination reference threshold M0, vehicle speed, respectively. A coefficient k12, a steering amount coefficient k13, a travel lane coefficient k14, and a travel lane difference coefficient k15 are set (step S230), and an interval coefficient k11, a vehicle speed coefficient k12, a steering amount coefficient k13, and a travel lane coefficient k14 are set as the determination reference threshold value M0. A value obtained by multiplying the travel lane difference coefficient k15 is set as the determination threshold value Mref (step S240). Here, in the embodiment, for each coefficient, the relationship between the parameter and the coefficient is determined in advance and stored in the ROM 34 as a coefficient setting map for each coefficient. When a parameter is given, the corresponding coefficient is derived from the stored map. And set it.

  FIG. 9 shows an example of a plurality of relationships between parameters and coefficients for setting the determination threshold value Mref, FIG. 10 shows an example of a coefficient setting map for the travel lane coefficient k14, and FIG. 11 shows the travel lane coefficient k15. The explanatory view explaining the example of a mode of setting up is shown. In FIG. 9, the right side is an example of a coefficient setting map. As shown in FIG. 9, the shorter the reference data interval D, the smaller the interval coefficient k11 across the value 1, the larger the vehicle speed V, the smaller the vehicle speed coefficient k12 across the value 1, and the larger the steering wheel steering amount St. The steerable amount coefficient k13 decreases from the value 1, the closer to the road the lane Lr, the smaller the lane coefficient k14, and the greater the lane difference ΔL (the farther the lane Lr is away from the lane Ls at the time of shooting) Each coefficient is set based on each parameter so that the lane difference coefficient k15 becomes smaller from the value 1. As for the steering amount coefficient k13, a value 1 is uniformly set in a range where the steering amount St of the steering wheel is not more than a predetermined amount as a dead zone in the vicinity of the value 0. Also, as shown in FIG. 10, the travel lane coefficient k14 is set by selecting a different coefficient setting map for each input road type and applying the travel lane Lr to the selected coefficient setting map. Can do. For example, in the road (a) on the left side of the figure (the road type is a two-way road with a road type), the smaller the traveling lane Lr (that is, the closer to the left side of the road), the smaller the value 1 is. The road lane coefficient k14 is set as shown in the figure, and the road (b) in the center in the figure (the road type is a one-way road and a three-lane road) and the road (c) on the right side in the figure (the road type is a one-way road) In the case of a 4-lane road), the travel lane coefficient k14 is set so that the travel lane Lr decreases from the value 1 as the travel lane Lr becomes farther from the center lane and closer to the left or right side of the road. Further, the travel lane difference coefficient k15 is set based on the travel lane difference ΔL, and as the travel lane Lr moves away from the shooting travel lane Ls to the left or right in the road width direction as shown in FIG. In other words, it is set so as to be smaller. The reason for setting each coefficient in this way will be described next.

  When the reference data interval D on the road on which the vehicle on which the navigation device 20 of the embodiment is mounted is traveling is relatively short, as described above, the determination data matches the reference data by the matching process. This is a case where there is a low chance of being determined, and a recognition failure of a landscape image that may be recognized as originally matching with the reference data is likely to occur. Therefore, when the reference data interval D is relatively short, the interval coefficient k11 is decreased to decrease the determination threshold value Mref, thereby making it easier to determine that the determination data matches the reference data by the matching process. Thus, it is possible to suppress omissions in recognition of landscape images. Further, when the vehicle speed V and the steering wheel amount St are relatively large, the moving speed of the feature point in the landscape image taken by the camera 59 (the steering wheel steering amount St is particularly in a direction corresponding to the direction opposite to the turning direction of the vehicle. This is a case where the movement speed is relatively large. Therefore, the larger the vehicle speed V and the steering wheel amount St are, the smaller the vehicle speed coefficient k12 and the steering amount coefficient k13 are set to decrease the determination threshold value Mref, thereby making it easier to determine that the landscape image and the reference data match. And omission of recognition of landscape images can be suppressed.

  Further, when the driving lane Lr is close to the roadside, the vehicle position is close to the roadside on the left side or the right side of the center in the width direction of the driving road, and the feature point in the landscape image taken by the camera 59 The movement speed of the feature point on the left side of the image is closer to the left side of the road than the center in the width direction of the road, and the feature point on the right side of the image is closer to the right side of the road than the center of the road width direction. This is also the case where the recognition failure of the landscape image is likely to occur. Therefore, by reducing the driving lane coefficient k14 and decreasing the determination threshold Mref as the driving lane Lr is closer to the roadside, it can be easily determined that the landscape image and the reference data match. Image recognition omission can be suppressed. In addition, when the travel lane difference ΔL is large (when the travel lane Lr is separated from the travel lane Ls at the time of shooting), the vehicle position at the time of shooting a landscape image in which the vehicle position has obtained reference data in the width direction of the road that is running A feature point in a landscape image photographed by the camera 59 (a feature on the left side of the image when moving away from the vehicle position at the time of photographing the landscape image obtained with reference data). On the other hand, when moving away from the vehicle position at the time of shooting the landscape image from which the reference data was obtained, the moving speed of the feature point on the right side of the image is relatively high, which also causes the recognition failure of the landscape image. Therefore, the smaller the travel lane difference ΔL is, the smaller the travel lane difference coefficient k15 is set to reduce the determination threshold value Mref, thereby making it easier to determine that the landscape image matches the reference data. Recognition failure can be suppressed.

  When the determination threshold value Mref is thus set, the matching rate Mr between the determination data and the reference data is calculated (step S250), and the calculated matching rate Mr is compared with the determination threshold value Mref (step S260). Here, the matching rate Mr represents the degree of matching between the determination data and the reference data. For example, the corresponding pixels of both data (the total number of pixels and the aspect ratio are the same) as a binarized image. Can be calculated as a ratio of the number of pixels having the same value (value 0 or value 1) to the total number of pixels.

  When the calculated matching rate Mr is less than the determination threshold value Mref, it is determined that the determination data and the reference data do not match, and the reference data of the shooting position and shooting direction that match the estimated host vehicle position and the vehicle traveling direction, and It is determined whether or not a total of three determination processes, that is, a total of three reference data of the two reference data before and after the road and one determination data, has been performed (step S270). If the determination process has not been performed three times in total, the process returns to step S200, and the reference position of the photographing position that matches the estimated host vehicle position and the vehicle traveling direction previously input in step S200 is replaced without changing the determination data. Instead of data, reference data (one reference data ahead) in the vehicle traveling direction is input on the road at the photographing position, and the processes in steps S200 to S260 are repeated. Again, when the matching rate Mr is less than the determination threshold value Mref and the determination process is not performed three times in total (steps S260 and S270), the process returns to step S200, and the determination data is not changed and is first changed to step S200. Instead of the reference data of the shooting position that matches the estimated host vehicle position and the vehicle traveling direction input in step 1, the reference data immediately preceding the vehicle traveling direction on the road at the shooting position is input, and the processes of steps S200 to S260 are performed. repeat.

  When the determination result that the matching rate Mr is less than the determination threshold value Mref is obtained three times (steps S260 and S270), the estimated vehicle position is determined as the vehicle position (step S280), and the vehicle position determination process is performed. End the routine. On the other hand, if it is determined that the matching rate Mr is equal to or greater than the determination threshold value Mref while repeating such processing three times, the shooting position corresponding to the reference data that matches the determination data at that time is determined as the own vehicle position. (Step S290), and the vehicle position determination processing routine ends. By such processing, it is possible to specify the vehicle position that is more accurate than the estimated vehicle position estimated by GPS navigation, autonomous navigation, or the like in the location processing. When the vehicle position is specified in this way, the next vehicle position is estimated by GPS navigation, autonomous navigation, or the like with the specified vehicle position as a reference.

  The processing of each step of this routine is basically performed by the location processing unit 60 of the electronic control unit 30, and the creation of determination data in the input processing of step S200 is performed by the image processing unit 66 of the electronic control unit 30. It is.

  According to the navigation device 20 of the embodiment described above, a plurality of reference data obtained by extracting feature points of a landscape image taken from a camera 59 mounted on the road with an interval in the direction of travel are respectively taken correspondingly. It is stored in the reference data DB 44 in association with the position, and a matching process is performed to determine whether or not a landscape image taken from the camera 59 mounted on the vehicle matches a plurality of reference data. In determining the vehicle position that is the current position of the vehicle based on the shooting position corresponding to the reference data determined to be, the reference data interval D on the road of the adjacent reference data has a small road width. (In the embodiment, the smaller the lane number Ln, the narrower the lane width Lw, the narrower the sidewalk width Pw), the adjustment is made to be shorter. From, it is possible to increase the opportunities for the reference data and determination data are determined to be coincident by the matching process. As a result, the vehicle position can be determined more appropriately.

  Further, according to the navigation device 20 of the embodiment, the reference data interval D on the road of the adjacent reference data is smaller as the curvature radius R of the road is smaller and the distance Dc from the nearest intersection on the road is shorter. Since the adjustment is performed as described above, it is possible to increase the chance that the determination data and the reference data are determined to match by the matching process. Further, the threshold value for judgment Mref for comparison with the matching rate Mr between the judgment data and the reference data is adjusted as the reference data interval D on the road of the adjusted adjacent reference data is shorter and the vehicle speed V is larger. Since the adjustment is made such that the larger the steering amount St, the closer the driving lane Lr is to the side of the road, and the farther the driving lane Lr is from the driving lane Ls at the time of shooting, the matching data and the judgment data are equalized. It can be easily determined that it is done. As a result, the vehicle position can be determined more appropriately.

  In the navigation device 20 of the embodiment, the reference data interval D on the road of the adjacent reference data is set such that the smaller the lane number Ln of the target road, the narrower the lane width Lw, the narrower the sidewalk width Pw, the smaller the curvature of the target road. The smaller the radius R is, the shorter the distance Dc from the nearest intersection on the road is, the shorter the adjustment is, that is, the adjustment is made based on five parameters. Instead of or in addition to the adjustment based on the lane width Lw and the sidewalk width Pw, the reference data interval D may be adjusted so as to be shorter as the width Dw of the target road is narrower. Further, the reference data interval D may be adjusted based on only a part (one or more) of six parameters obtained by adding the road width Dw to these five parameters, Adjustment may be made based on other parameters in addition to the six parameters.

  Therefore, for example, the reference data interval D may be adjusted so as to become shorter as the width Dw of the target road becomes narrower without adjusting based on parameters other than the width Dw of the target road.

  In the navigation device 20 according to the embodiment, the threshold value Mref used for determining the matching rate Mr between the determination data and the reference data is such that the shorter the reference data interval D, the higher the vehicle speed V, and the larger the steering wheel steering amount St. As the traveling lane Lr is closer to the side of the road and the traveling lane difference ΔL is larger, the adjustment is made to be smaller, that is, the adjustment is made based on the five parameters. The determination threshold value Mref may be adjusted based only on an arbitrary part (one or more) of parameters. Further, the determination reference threshold value M0 may be used as it is as the determination threshold value Mref.

  In the navigation device 20 of the embodiment, the determination threshold value Mref used for determining the matching rate Mr between the determination data and the reference data is adjusted so as to decrease as the travel lane Lr is closer to the roadside. Since the determination threshold value Mref may be adjusted to be smaller as the vehicle position is closer to the roadside in the width direction of the running road, the vehicle position in the width direction of the road can be determined without detecting the driving lane Lr. The determination threshold value Mref may be adjusted based on the detected position.

  In the navigation device 20 according to the embodiment, the determination threshold value Mref used for determining the matching rate Mr between the determination data and the reference data is adjusted so as to decrease as the travel lane Lr moves away from the shooting travel lane Ls. However, since the determination threshold value Mref may be adjusted to be smaller as the vehicle position moves away from the vehicle position at the time of shooting the landscape image in which the reference data is obtained in the width direction of the road on which the vehicle is traveling, the traveling lane Lr is detected. Alternatively, the vehicle position in the width direction of the road may be detected by image processing on the determination data, and the determination threshold value Mref may be adjusted based on the detected position.

  In the embodiment, the position determination device according to the present invention is applied to the navigation device 20 including the display 22 and the HDD 40. However, for example, the location of the electronic control unit 30 is connected to a server communicably connected to the navigation device including the display. The server may function as the position determination device of the present invention by performing the function of the processing unit 60 and a part of the function of the image processing unit 66 necessary for the location processing. Further, instead of the navigation device 20, devices such as a digital camera, a portable terminal, and a drive recorder may function as the position determination device of the present invention. In this case, such a device may be installed in the vehicle interior, and the vehicle position may be determined using a landscape image taken by a camera provided in the device.

  In the embodiments, the position determination device of the present invention is applied to the navigation device 20. However, the position determination method may be used, and each step of the position determination method may be realized by one or more computers. The program may be in the form of Further, such a program may be stored in a recording medium.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problems will be described. In the embodiment, a plurality of reference data is stored in the reference data DB 42 of the HDD 40, and a matching process is performed to determine whether or not a landscape image captured from the camera 59 mounted on the vehicle matches the plurality of reference data. The location processing unit 60 and the image processing unit of the electronic control unit 30 that execute the host vehicle position determination processing routine of FIG. 7 that determines the host vehicle position based on the shooting position corresponding to the reference data determined to match. Part of 66 corresponds to a “position determination device”.

  The correspondence between the main elements of the embodiment and the main elements of the invention described in the column of means for solving the problem is the same as that of the embodiment described in the column of means for solving the problem. Therefore, the elements of the invention described in the column of means for solving the problems are not limited. That is, the interpretation of the invention described in the column of means for solving the problems should be made based on the description of the column, and the examples are those of the invention described in the column of means for solving the problems. It is only a specific example.

  As mentioned above, although the form for implementing this invention was demonstrated using the Example, this invention is not limited at all to such an Example, In the range which does not deviate from the summary of this invention, it is with various forms. Of course, it can be implemented.

  The present invention can be used in the manufacturing industry of navigation devices and position determination devices.

  10 navigation system, 12 in-vehicle device, 20 navigation device, 22 display, 24 touch panel, 26 speaker, 30 electronic control unit, 32 CPU, 34 ROM, 36 RAM, 38 flash memory, 40 hard disk drive (HDD), 42 for map data Database (Map Data DB), 44 Reference Data Database (Reference Data DB), 50 GPS Receiver, 52 Vehicle Speed Sensor, 54 Acceleration Sensor, 56 Direction Sensor, 58 Steering Amount Sensor, 59 Camera, 60 Location Processing Unit, 62 Map Display processing unit, 64 navigation processing unit, 66 image processing unit.

Claims (9)

A plurality of reference data obtained by extracting characteristic parts of a landscape image taken from an in-vehicle camera at intervals in the traveling direction on the road are stored in association with the corresponding positions on the map, and taken from the in-vehicle camera. Matching processing is performed to determine whether or not the scenery image to be matched and the plurality of reference data match, and based on the position on the map corresponding to the reference data determined to match by the matching processing A position determination device for determining a position of a vehicle on a map,
The distance interval on the road of the adjacent reference data is adjusted so as to be shorter as the width of the road is smaller.
Position determination device. The position determination device according to claim 1,
The distance between the adjacent reference data on the road is adjusted so as to be shorter as the curvature radius of the road is smaller.
Position determination device. The position determination device according to claim 1 or 2,
The distance between adjacent reference data on the road tends to be shorter as the number of lanes on the road is smaller, tends to be shorter as the lane width of the road is narrower, and tends to be shorter as the sidewalk width of the road is narrower. Adjusted to be
Position determination device. The position determination device according to any one of claims 1 to 3,
The distance interval on the road of the adjacent reference data is adjusted so as to become shorter as the distance from the nearest intersection on the road is shorter,
Position determination device. The position determination device according to any one of claims 1 to 4,
The matching process is performed when the degree of coincidence between the determination data obtained by performing predetermined image processing for extracting a characteristic part from a landscape image photographed from a vehicle-mounted camera and the reference data is equal to or greater than a determination threshold value Is determined, and is determined not to match when the degree of matching is less than the determination threshold,
The determination threshold value is adjusted so as to be smaller as the distance interval on the road of the adjusted adjacent reference data is shorter.
Position determination device. The position determination device according to claim 5,
The determination threshold tends to decrease as the vehicle speed increases, tends to decrease as the steering wheel amount increases, and tends to decrease as the vehicle position is closer to the side of the road in the width direction of the traveling road. The vehicle position in the width direction is adjusted to be at least one of the tendency to become smaller as the distance from the vehicle position at the time of capturing the landscape image obtained the reference data,
Position determination device.   A navigation device comprising the position determination device according to any one of claims 1 to 6 and performing route guidance to a destination using a position on a map of the vehicle determined by the position determination device. A plurality of reference data obtained by extracting characteristic parts of a landscape image taken from an in-vehicle camera at intervals in the traveling direction on the road are stored in association with the corresponding positions on the map, and taken from the in-vehicle camera. A matching process for determining whether or not the scenery image to be matched and the plurality of reference data match, and a position on the map corresponding to the reference data determined to match by the matching process A position determination method executed by a position determination device that executes a step of determining a position of a vehicle on a map based on
The distance interval on the road of the adjacent reference data is adjusted so as to be shorter as the width of the road is smaller.
Position determination method. 9. A non-transitory computer-readable storage medium storing a program for causing each of the one or more computers to function as the position determining device by executing each step of the position determining method according to claim 8 by one or more computers .

Images